The structure of casting particularly the macrostructures gets affected by various factors and one of the important factors among this is freezing range. This is because the freezing range varies for instance pure metals have lesser freezing range and therefore the process of solidifications is done one layer after another which contributes columnar grains for macrostructure.
Some examples in which range of freezing is shorter are steels and casting and so on. In contrast the metals with longer range of freezing the process of solidification gets started out at number of points, which contributes to equi-azed grains for macrostructure. Some examples in which range of freezing is longer are aluminum, sand casting and so on.
The process of solidification can be modeled by considering and treating both liquid and solid as a fluid whose attributes gets changed over the freezing range. The use of proper alloys plays an essential part in phenomenon of solidification since uniform freezing of the casting is determined by this aspect.
Also the shrinkage defect type depends a lot on freezing range. Thus proper care and analysis must be made to have freezing range maintained properly to reduce shrinkage defects and improve final quality of product.